1. Field of the Invention
The present invention relates to a computer program product, system, and method for providing a reserved data area to use to extend a data set.
2. Description of the Related Art
In certain computing environments, multiple host systems may configure data sets in volumes configured in a storage system, such as interconnected storage devices, e.g., a Direct Access Storage Device (DASD), Redundant Array of Independent Disks (RAID), Just a Bunch of Disks (JBOD), etc. Data sets are comprised of extents, which may comprise any grouping of tracks and data storage units. The Z/OS® operating system from International Business Machines Corporation (“IBM”) has a Volume Table of Contents (VTOC) to provide information on data sets of extents configured in the volume, where the VTOC indicates the location of tracks, extents, and data sets for a volume in storage.
The VTOC is comprised of contiguous addresses usually starting from the first track of the volume. If the VTOC runs out of space and needs more space for records to define additional data sets configured in the volume, then the user may use a utility program to move the entire volume to a new storage area in which the VTOC is configured with additional space to accommodate the number of data sets being configured in the volume. Another technique to avoid the VTOC running out of space is to overprovision space in the VTOC beyond the expected number of data sets in case more data sets are configured than expected.